There is a product line in the food industry that is generally referred to as “case-ready” product. Case-ready product can include meat and vegetables, as well as other food products, in packages comprising a container and a cover. The cover is preferably clear for viewing the product in the container. Often, the product is fresh and needs to be maintained in an environment that prevents contamination and premature spoilage. Case-ready product packages preferably include a plastic sheet cover substantially the same size as the container opening wherein the cover is sealed to an upper portion (generally, a rim) of the container.
The interiors of case-ready containers, because they are sealed, can be flushed with various gases to help preserve the freshness of the food product to extend shelf life. Shelf life is important to food processors, retailers and consumers in order to reduce costs and to provide safety for the end consumer.
In case-ready products where the cover is heat-sealed to the upper portion of the container, the use of flushing gases is particularly important to provide a seal of the required integrity. Machines have been designed to introduce a gas into the container while simultaneously heat-sealing a durable film around the rim of the container, where the containers generally comprise a polymeric (plastic) tray-type container. The machines include sealing bars that apply pressure and heat to the film, creating a heat seal to secure the cover to the container. When executed correctly, a pillow of gas is captured under the covering film. However, in cases where a good seal is not formed between the container and the cover (for example, by the presence of moisture, fat and/or protein on the sealing area of the container) the cover will not be properly secured and the product will have to be re-worked. This adds to the cost of producing products and/or elevates the risk of premature failure of the product. Re-working requires that the container be removed from the production line and placed into the machine for re-processing, and typically requires a worker to remove foreign materials from the sealing area of the container.
Currently in the meat industry, operators manually wipe the tops of the containers with towels prior to sealing. The use of operators for cleaning receptacles is expensive and sometimes results in receptacles being missed or not cleaned uniformly. In addition, when operators use towels to manually remove contaminants from the receptacles, it is up to the individual operator to determine when a towel should be disposed of and a new towel used. This can lead to sporadic quality of cleaning and can introduce the transfer of bacteria and other towel contaminants between and into receptacles.
It is also known in the food processing industry to utilize air jets to clean the tops of containers prior to sealing. This method can be successfully used with food products that tend to leave loose particulate matter or water on the sealing surface of the receptacles. However, contaminants such as proteins, fats and starches adhere more securely to the sealing surfaces. Air streams are not effective for the removal of these contaminants, to a point where sealing can be effected.
Another limitation common to most prior art meat packaging machines is that each machine is specifically developed and sized to accommodate specific package dimensions. Therefore, as container sizes change, a typical packaging machine must be taken out of service and essentially re-built to properly transport and fill the different-dimensioned package. Alternatively, a packaging facility may utilize several different pieces of apparatus, each “sized” for a different container size. As a result, the “floor space” required to perform the packaging is significantly increased, which is a concern for environments where refrigerated packaging facilities are used.
Thus, there is a need for an improved apparatus and method for packaging foodstuffs, such as meats, that overcomes the aforementioned problems.